Hello!
I'm working on a pitching machine capable to throw balls through two wheels.
So I'm looking for a motor or two capable of giving enough speed to the wheels in order to get nice speed.
I have the arduino shield motor.
I think that 0.5 HP will do the work, but I'm not sure and I don't even know where can I find this kind of DC motors and if are suitable with my arduino uno.
Motors for electric scooters come in a range of power up to around 600 watts or so. You can also use a scooter speed control to drive the motr. All you need to figure out is how to hack it so's you can use the arduino to act as the control.
To accelerate a ball you might not need that much power, just flywheels to store the energy - each use will slow the flywheels and then it takes a little while to recover to speed - the motor then only has to supply the average power rather than peak power.
Its a nice exercise in mechanics to work out the flywheel mass & size and motor specifications I think
yes, I would strongly reccomend the flywheel approach. use a very heavy wheel to throw the ball, and shazam you have a two in one flywheel/ball thrower.
for motor control, once you have picked a motor (whataver you can cut out of some junk nearby is a good starting point) I would grab a electronic speed controller (ESC) from robotmarketplace.com they have a good selection. they are mostly meant to be controlled by RC remotes, which are basically servos, which your arduino can mimic very easily. no shield needed.
do the motors need to be DC? could it be easier to find a AC motor in the trash? no idea what you would neeed for a speed controller though at that point
1400Kv means it spins at 1400RPM per volt. At 1400RPM it would be throwing 40mph fastballs with a 10" wheel. At the peak speed of the motor it would probably be throwing the rubber off the wheel
To the OP you're going to want to look for a slower motor and that's probably going to be a brushed motor.